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Example: filters program

0 This example uses chirp_filters() to generate two chirps $\pi/2$ out of phase with each other. It also demonstrates a different memory allocation option than the phase_evoln example program. Includes/filters.tex

Notice that we only allocated enough memory for 10000 points, and we know from the output from the previous example that this chirp takes 13515 points. Therefore running this example results in following error message printed to stderr:

GRASP:phase_frequency():Allocated memory is filled up before
reaching the maximum frequency requested for this chirp.
Orbital Frequency Reached(Hz): 98.867607, Number of points: 10000
Terminating chirp. Termination code set to:     2001
Returning to calling routine.

However, even though the routine ran out of memory it still computed the first 10000 points of the chirp and returned them in the arrays *ptrptrCos[0..steps_alloc-1] and
[4]*ptrptrSin[0..steps_alloc-1].

Figure: The zero-phase chirp waveform from a $2 \times 1.4 M_\odot$ binary system, starting at an orbital frequency of 60 Hz. The top graph shows the frequency of the dominant quadrupole radiation as a function of time, and the middle graph shows the waveform. The bottom graph shows a 40-msec stretch near the final inspiral/plunge.



Bruce Allen 2000-11-19